The long-range research goals have remained basically the same for several years. We have continued to study a variety of heterogeneous and homegeneous charge transfer processes for the purpose of attaining an understanding of transfer mechanisms. These have over the past few years been directed to the study of stoichiometry (n values), energetics (Eo' values) and kinetic parameters of bio-electron transfer components such as heme proteins through coupling via a mediator-titrant to electrodes. The indirect coulometric titration method has proved to be particularly valuable in these studies and currently we plan to extend this method to the study of cytochrome c oxidase and other components present in intact submitochrondrial particles. An important part of our efforts has been the continued development of theory and methodologies assoicated with charge transfer processes. For example, we have devoted major effort for several years to spectroelectrochemistry using optically transparent electrodes. More recently, our attention has been directed toward the design, fabrication, testing and analysis of chemically modified surfaces for the purpose of creating catalytic and/or selective electrodes.